witch engin fits

I have a 1995 pontiac grand am se with a 3100 (3.1L) engin and my motor is dead , What i wanna know is can i put a diffrent motor in than the one that i have (ex a 3.1 from a grand prix or even a 3.1 from a grand am but a 1996 istead??) so if anybody know can u tel witch engin fits without having to change all the monts for the engin. from witch car to witch year!! thanks!!!..